Experimental and numerical study of tooth finishing processes contribution to gear noise

The contribution of gear tooth flank surface micro-finish on gear noise has not yet been taken into consideration. This paper is devoted to study the simultaneous effect of tooth roughness and lubricant viscosity on automotive gear vibrations. The vibrations performances were evaluated on an instrumented test rig under both dry and wet conditions. A non-destructive replication technique coupled to 3D optical measures was used to acquire the flanks topographies, which were characterized using multiscale decomposition. A three-dimensional finite element simulation of a helical gear was performed to assess the micro-scales impact on gear noise. Numerical representative surfaces morphologies were introduced into the simulation and compared through the transmission error calculation. Results have shown gear noise dependence on tooth finishing processes. •The vibrational behavior of gears finished by three processes was tested.•Multiscale surface characterization was used to define processes signatures.•Experiments and simulations in dry conditions show the influence of roughness.•Gear vibrations are most influenced by the waviness surface scales in wet conditions.•The results highlighted the pertinence of this developed methodology.